Follow-up Care of Critically Ill Patients With Acute Kidney Injury: A Cohort Study

Rationale & Objective: To evaluate follow-up care of critically ill patients with acute kidney injury (AKI). Study Design: Retrospective cohort study. Setting & Participants: Patients admitted to the intensive care unit (ICU) with AKI in Alberta, Can-ada from 2005 to 2018, who survived to discharge without kidney replacement therapy or estimated glomerular filtration rate <15 mL/min/1.73 m2. Exposure: AKI (defined as & GE;50% or & GE;0.3 mg/dL serum creatinine increase). Outcomes: The primary outcome was the cumu-lative incidence of an outpatient serum creatinine and urine protein measurement at 3 months post-discharge. Secondary outcomes included an outpatient serum creatinine or urine protein mea-surement or a nephrologist visit at 3 months postdischarge. Analytical Approach: Patients were followed from hospital discharge until the first of each outcome of interest, death, emigration from the province, kid-ney replacement therapy (maintenance dialysis or kidney transplantation), or end of study period (March 2019). We used non-parametric methods (Aalen-Johansen) to estimate the cumulative incidence functions of outcomes accounting for competing events (death and kidney replacement therapy). Results: There were 29,732 critically ill adult pa-tients with AKI. The median age was 68 years (IQR, 57-77), 39% were female, and the median baseline estimated glomerular filtration rate was 72 mL/min/1.73 m2 (IQR, 53-90). The cumulative incidence of having an outpatient creatinine and urine protein measurement at 3 months post-discharge was 25% (95% CI, 25-26). At 3 months postdischarge, 64% (95% CI, 64-65) had an outpatient creatinine measurement, 28% (95% CI, 27-28) had a urine protein measurement, and 5% (95% CI, 4-5) had a nephrologist visit. Limitations: We lacked granular data, such as urine output. Conclusions: Many critically ill patients with AKI do not receive the recommended follow-up care. Our findings highlight a gap in the transition of care for survivors of critical illness and AKI.